Coking loading tail gas recovery treatment system

Abstract

The utility model relates to a coking loading tail gas recovery processing system which comprises a loading crane pipe with a tail gas recovery function, a tail gas header pipe pressure adjusting system, a nitrogen injection system, a tail gas buffer tank, a tail gas pipeline steam blowing and heat tracing heat preservation system, an oxygen content detection and emergency cut-off system and a nitrogen pipeline. The loading crane pipe is connected with the tail gas header pipe pressure adjusting system and is connected to the nitrogen injection system; the nitrogen pipeline is also connected to the nitrogen injection system; the nitrogen injection system, the tail gas buffer tank and the oxygen content detection and emergency cut-off system are connected in sequence; the content detection and emergency cut-off system performs cut-off action according to a set oxygen content upper limit; the tail gas pipeline steam blowing and heat tracing heat preservation system conducts steam blowing and heat tracing on the exterior of a pipeline containing tail gas.

Description

Technical Field

[0001] This utility model relates to a method for treating exhaust gas from coking truck loading, specifically a coking truck loading exhaust gas recovery and treatment system. Background Technology

[0002] The coking plant of a steel company involves loading various chemical products, such as crude benzene, wash oil, and anthracene oil, onto trucks. Currently, domestic enterprises do not fully implement closed-loop loading and unloading procedures. Some enterprises often directly open the manholes on the truck roof during unloading, allowing a large amount of air to enter the tanker truck. When materials are loaded again, this produces exhaust gas containing approximately 18-20% oxygen. Due to the high oxygen content and high concentration of combustible components in this exhaust gas, it cannot be directly recovered through a negative pressure gas system or sent to an incinerator for incineration. Currently, most companies use solvent washing to directly release the exhaust gas from vehicle loading into the air, but the content of non-methane total hydrocarbons far exceeds the requirements of existing national standards. Other companies use a process of "deep condensation + activated carbon / carbon fiber adsorption / incineration" to treat benzene-based exhaust gas, but this process has certain problems, mainly: 1) the cooling temperature does not reach the design value, and the exhaust gas emission indicators do not meet the standards; 2) due to the complex composition of the exhaust gas and the presence of a certain amount of easily crystallizing substances such as naphthalene, it easily causes blockage of the heat exchanger tubes in the deep condensation system, and cleaning is inconvenient; 3) the initial investment and operating costs are high. Utility Model Content

[0003] This utility model provides a coking plant loading exhaust gas recovery and treatment system and process, which mainly consists of a loading arm with exhaust gas recovery, an exhaust gas main pipe pressure regulation system, a nitrogen injection system, an exhaust gas buffer tank, an exhaust gas pipeline steam purging and heat tracing insulation system, and an oxygen content detection and emergency shut-off system. This system uses nitrogen as a power source to introduce loading exhaust gas into the system while simultaneously using nitrogen as an inert gas to dilute the oxygen content in the loading exhaust gas, ensuring it meets the conditions for introduction into the coal gas negative pressure system, thereby solving the current problem of coking plant loading exhaust gas treatment.

[0004] The purpose of this invention is to solve the problem that the existing vehicle exhaust gas has a high oxygen content and cannot be directly entered into the gas negative pressure system for recovery and treatment. The "deep condensation + activated carbon / carbon fiber adsorption / incineration" treatment process has many drawbacks and cannot treat vehicle exhaust gas containing other easily crystallizing media such as tar and naphthalene oil.

[0005] The present invention adopts the following technical solution:

[0006] A coking plant exhaust gas recovery and treatment system includes a loading arm with exhaust gas recovery, an exhaust gas main pipe pressure regulation system, a nitrogen ejector system, an exhaust gas buffer tank, an exhaust gas pipeline steam purging and heat tracing insulation system, an oxygen content detection and emergency shut-off system, and a nitrogen pipeline. The loading arm and the exhaust gas main pipe pressure regulation system are connected to and connected to the nitrogen ejector system. The nitrogen pipeline is also connected to the nitrogen ejector system. The nitrogen ejector system's exhaust gas buffer tank and oxygen content detection and emergency shut-off system are connected in sequence. The oxygen content detection and emergency shut-off system shuts off the system according to a set upper limit for oxygen content. The exhaust gas pipeline steam purging and heat tracing insulation system purifies and heats the exterior of the pipeline containing exhaust gas.

[0007] Preferably, the loading arms include loading arms for Class A and B liquids and loading arms for Class C liquids, and all loading arms are connected in parallel; the loading arms for Class A and B liquids are connected to the exhaust gas main pressure regulating system through a loading exhaust gas pipe, and a flame arrester is installed on the Class A and B liquid loading exhaust gas pipe; the loading arms for Class C liquids are connected to the exhaust gas main pressure regulating system through a loading exhaust gas pipe, and no flame arrester is installed on the Class C liquid loading exhaust gas pipe.

[0008] Preferably, the oxygen content detection and emergency shut-off system is connected to the exhaust gas collection main pipe, and an emission channel is provided between the two.

[0009] Preferably, the nitrogen ejection system is a Venturi structure, wherein the nitrogen pipeline is the inlet channel of the Venturi structure, and the pipeline where the exhaust gas main pressure regulating system is located is a negative pressure intake channel of the Venturi structure.

[0010] Preferably, gate valves are provided at both the front and rear of the exhaust gas buffer tank.

[0011] Furthermore, gate valves are provided at the front of the exhaust pipes for Class A and B liquids and Class C liquids, and shut-off valves are provided at the front of the steam purging and heat tracing system.

[0012] A coking truck loading exhaust gas recovery and treatment process utilizes the aforementioned coking truck loading exhaust gas recovery and treatment system. The loading exhaust gas generated by the tanker truck is collected in a closed system via a loading arm with exhaust gas recovery and related pipelines. The collected exhaust gas is then injected into the exhaust gas collection system under negative pressure created by a nitrogen injection system. After thorough mixing with nitrogen, the mixture enters an exhaust gas buffer tank for further homogenization. The homogenized exhaust gas is then sent to a coal gas negative pressure system after passing an online oxygen content detector test. When the oxygen content exceeds the standard, the main exhaust gas pipeline to the coal gas negative pressure system is quickly shut off, and the exhaust gas is discharged through a vent pipe. A main exhaust gas pipeline pressure regulating system installed between the loading arm and the nitrogen injection system precisely controls the negative pressure inside the tanker truck, i.e., the exhaust gas suction.

[0013] Preferably, it includes the following steps:

[0014] S1. Reliably connect the loading arm with exhaust gas recovery to the tank truck and turn on the steam tracing system of the exhaust gas pipeline.

[0015] S2. One-button start of the vehicle exhaust treatment system. The vehicle exhaust treatment system will automatically perform the following operations.

[0016] S21. Close the quick-cut-off valve on the exhaust gas main pipe and open the quick-release valve on the exhaust gas main pipe at the same time.

[0017] S22. Gradually open the nitrogen flow regulating valve in the nitrogen ejector system until the flow meter reaches the first set value;

[0018] S23. When the reading of the online oxygen content detector reaches the second set value, close the quick release valve on the tail gas main pipe and open the quick shut-off valve on the tail gas main pipe to introduce the tail gas into the coal gas negative pressure system. At the same time, interlock the quick release valve, the quick shut-off valve and the online oxygen content detector.

[0019] S24. Put the exhaust gas pressure regulating valve at the exhaust gas inlet pipe into automatic mode, control the pressure transmitter reading before the pressure regulating valve to reach the third set value, and introduce the loaded exhaust gas into the coal gas negative pressure system.

[0020] S25. When the reading of the online oxygen content detector reaches the fourth set value, close the quick shut-off valve on the exhaust gas main pipe and open the quick release valve on the exhaust gas main pipe to release the exhaust gas into the air.

[0021] S26. Increase the opening of the nitrogen flow regulating valve in the nitrogen ejector system until the flow meter reaches the fifth set value, then purge and replace the exhaust gas pipeline.

[0022] S27. When the reading of the online oxygen content detector returns to the second set value, close the quick release valve on the tail gas main pipe and open the quick shut-off valve on the tail gas main pipe to continue to introduce tail gas into the coal gas negative pressure system. At the same time, interlock the quick release valve, the quick shut-off valve and the online oxygen content detector. Meanwhile, gradually reduce the opening of the nitrogen flow regulating valve until the nitrogen flow reaches the first set value.

[0023] S28. After loading is completed, the exhaust gas treatment system and nitrogen flow regulating valve will be turned off with one click.

[0024] S3. Disconnect the loading arm with exhaust gas recovery from the tank truck and shut off the steam tracing system of the exhaust gas pipeline.

[0025] The beneficial effects of this utility model are as follows:

[0026] 1) The closed-loop recovery of coking exhaust gas has been achieved, enabling safe and effective treatment of coking exhaust gas.

[0027] 2) It achieves one-button start / stop and automatic collection and treatment of vehicle exhaust fumes. Under normal circumstances, no manual intervention is required during the process.

[0028] 3) Multiple methods for preventing pipe blockage (such as steam tracing) are adopted, which can effectively prevent pipe blockage, reduce the occurrence of pipe blockage, and reduce the workload of daily inspection and maintenance.

[0029] 4) The system is simple and has low investment and operating costs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the coking truck exhaust gas recovery and treatment system of this utility model. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0032] This utility model proposes to use a nitrogen injection mixing + negative pressure exhaust gas recovery process to recover and treat the exhaust gas from the vehicle. It mainly consists of a loading arm with exhaust gas recovery, an exhaust gas main pipe pressure regulation system, a nitrogen injection system, an exhaust gas buffer tank, an exhaust gas pipeline steam purging and heat tracing insulation system, and an oxygen content detection and emergency shut-off system.

[0033] It can perform the following functions:

[0034] The loading arm with exhaust gas recovery is used to perform closed-loop recovery of the exhaust gas during loading.

[0035] A nitrogen ejection system is used to create negative pressure, drawing the vehicle exhaust gas into the system and mixing it thoroughly with nitrogen.

[0036] A tailpipe pressure regulating valve is used to control the negative pressure value inside the tanker truck and ensure the safety of the tanker truck.

[0037] It is equipped with an online oxygen content detection and emergency shut-off system to strictly control the oxygen content and avoid the impact of the oxygen content in the exhaust gas on the coal gas refining system;

[0038] Measures such as steam tracing, steam purging, and condensate discharge are implemented to prevent impurities such as naphthalene and tar in coking tail gas from easily crystallizing and clogging pipelines.

[0039] See Figure 1A coking plant exhaust gas recovery and treatment system includes a loading arm with exhaust gas recovery, an exhaust gas main pipe pressure regulation system, a nitrogen ejector system, an exhaust gas buffer tank, an exhaust gas pipeline steam purging and heat tracing insulation system, an oxygen content detection and emergency shut-off system, and a nitrogen pipeline. The loading arm and the exhaust gas main pipe pressure regulation system are connected to each other and to the nitrogen ejector system. The nitrogen pipeline is also connected to the nitrogen ejector system. The nitrogen ejector system's exhaust gas buffer tank and oxygen content detection and emergency shut-off system are connected in sequence. The oxygen content detection and emergency shut-off system shuts off the system according to a set upper limit for oxygen content. The exhaust gas pipeline steam purging and heat tracing insulation system purges and heats the exterior of the pipeline containing exhaust gas with steam.

[0040] See Figure 1 The loading arms include loading arms for Class A and B liquids and loading arms for Class C liquids, which are connected in parallel. The loading arms for Class A and B liquids are connected to the exhaust gas main pressure regulating system through a loading exhaust gas pipe, and a flame arrester is installed on the Class A and B liquid loading exhaust gas pipe. The loading arms for Class C liquids are connected to the exhaust gas main pressure regulating system through a loading exhaust gas pipe, and no flame arrester is installed on the Class C liquid loading exhaust gas pipe.

[0041] See Figure 1 The oxygen content detection and emergency shut-off system is connected to the waste collection main pipe, and there is also an emission channel between the two.

[0042] In this embodiment, the nitrogen ejection system is a Venturi structure, wherein the nitrogen pipeline is the inlet channel of the Venturi structure, and the pipeline containing the exhaust gas main pressure regulating system is the negative pressure suction channel of the Venturi structure. The principle of the Venturi structure is prior art, therefore its principle will not be explained in detail here.

[0043] See Figure 1 The exhaust gas buffer tank is equipped with gate valves at both the front and rear.

[0044] See also Figure 1 The crude benzene loading exhaust pipe and the tar loading exhaust pipe are both equipped with gate valves at the front end, and the steam purging and heat tracing insulation system is equipped with a shut-off valve at the front end.

[0045] A coking truck loading exhaust gas recovery and treatment process involves the closed-loop collection of loading exhaust gas generated by tank trucks via a loading arm equipped with exhaust gas recovery and related pipelines. The collected exhaust gas is then injected into the exhaust gas collection system under negative pressure created by a nitrogen injection system, where it is thoroughly mixed with nitrogen before entering an exhaust gas buffer tank for further mixing. After passing an online oxygen content test, the mixed exhaust gas is sent to a coal gas negative pressure system. If the oxygen content exceeds the standard, the main exhaust gas pipeline to the coal gas negative pressure system is quickly shut off, and the exhaust gas is discharged through a vent pipe. A main exhaust gas pressure regulating system located between the loading arm and the nitrogen injection system precisely controls the negative pressure inside the tank truck, i.e., the exhaust gas suction.

[0046] Specifically, the following steps are included:

[0047] S1. Reliably connect the loading arm with exhaust gas recovery to the tank truck and turn on the steam tracing system of the exhaust gas pipeline.

[0048] S2. One-button start of the vehicle exhaust treatment system. The vehicle exhaust treatment system will automatically perform the following operations.

[0049] S21. Close the quick-cut-off valve on the exhaust gas main pipe and open the quick-release valve on the exhaust gas main pipe at the same time.

[0050] S22. Gradually open the nitrogen flow regulating valve in the nitrogen ejector system until the flow meter reaches the first set value;

[0051] S23. When the reading of the online oxygen content detector reaches the second set value, close the quick release valve on the tail gas main pipe and open the quick shut-off valve on the tail gas main pipe to introduce the tail gas into the coal gas negative pressure system. At the same time, interlock the quick release valve, the quick shut-off valve and the online oxygen content detector.

[0052] S24. Put the exhaust gas pressure regulating valve at the exhaust gas inlet pipe into automatic mode, control the pressure transmitter reading before the pressure regulating valve to reach the third set value, and introduce the loaded exhaust gas into the coal gas negative pressure system.

[0053] S25. When the reading of the online oxygen content detector reaches the fourth set value, close the quick shut-off valve on the exhaust gas main pipe and open the quick release valve on the exhaust gas main pipe to release the exhaust gas into the air.

[0054] S26. Increase the opening of the nitrogen flow regulating valve in the nitrogen ejector system until the flow meter reaches the fifth set value, then purge and replace the exhaust gas pipeline.

[0055] S27. When the reading of the online oxygen content detector returns to the second set value, close the quick release valve on the tail gas main pipe and open the quick shut-off valve on the tail gas main pipe to continue to introduce tail gas into the coal gas negative pressure system. At the same time, interlock the quick release valve, the quick shut-off valve and the online oxygen content detector. Meanwhile, gradually reduce the opening of the nitrogen flow regulating valve until the nitrogen flow reaches the first set value.

[0056] S28. After loading is completed, the exhaust gas treatment system and nitrogen flow regulating valve will be turned off with one click.

[0057] S3. Disconnect the loading arm with exhaust gas recovery from the tank truck and shut off the steam tracing system of the exhaust gas pipeline.

[0058] The above are preferred embodiments of the present utility model. Those skilled in the art can make various changes or improvements based on this. Without departing from the overall concept of the present utility model, these changes or improvements should all fall within the scope of protection claimed by the present utility model.

Claims

1. A coking truck exhaust gas recovery and treatment system, characterized in that: This includes a loading arm with exhaust gas recovery, an exhaust gas main pressure regulation system, a nitrogen ejector system, an exhaust gas buffer tank, an exhaust gas pipeline steam purging and heat tracing insulation system, an oxygen content detection and emergency shut-off system, and a nitrogen pipeline. The loading arm and exhaust manifold pressure regulation system are connected to the nitrogen injection system; the nitrogen pipeline is also connected to the nitrogen injection system. The nitrogen ejector system exhaust gas buffer tank and the oxygen content detection and emergency shut-off system are connected in sequence; the content detection and emergency shut-off system performs a shut-off action according to the set upper limit of oxygen content; The exhaust gas pipeline steam purging and heat tracing system performs steam purging and heat tracing on the exterior of the pipeline containing exhaust gas.

2. The coking exhaust gas recovery and treatment system as described in claim 1, characterized in that: The loading arms include loading arms for Class A and B liquids and loading arms for Class C liquids, and all loading arms are connected in parallel. The loading arm for Class A and B liquids is connected to the exhaust manifold pressure regulation system via the loading exhaust pipe, and a flame arrester is installed on the Class A and B liquid loading exhaust pipe. The loading arm for Class C liquids is connected to the exhaust manifold pressure regulation system via the loading exhaust pipe, and no flame arrester is installed on the Class C liquid loading exhaust pipe.

3. The coking exhaust gas recovery and treatment system as described in claim 1, characterized in that: The oxygen content detection and emergency shut-off system is connected to the exhaust gas collection main pipe, and an emission channel is provided between the two.

4. The coking exhaust gas recovery and treatment system as described in claim 1, characterized in that: The nitrogen ejection system is a Venturi structure, wherein the nitrogen pipeline is the inlet channel of the Venturi structure, and the pipeline where the exhaust gas main pressure regulation system is located is a negative pressure intake channel of the Venturi structure.

5. The coking exhaust gas recovery and treatment system as described in claim 2, characterized in that: Gate valves are installed at both the front and rear of the exhaust gas buffer tank.

6. The coking exhaust gas recovery and treatment system as described in claim 5, characterized in that: Each of the exhaust gas pipelines is equipped with a gate valve at the front end, and the steam purging and heat tracing system is equipped with a shut-off valve at the front end.

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